The purpose of this research intended to measure class-teacher's leadership behavior in a junior high school, based on PM leadership theory and to examine its validity by investigating the relationship between leadership types and pupil's morale variables. A proper questionnaire was designed in order to rate the teacher's leadership and pupil's morale. The data from 2498 pupils were used for the analysis. The results were as follows.(1) By factor analysis of leadership items, six factors were found and twenty-four items were selected to measure P and M behavior.(2) By factor analysis of morale items, four factors were found as external criterion variables.(3) Teachers were classified into four types, PM-type, P-type, M-type, pm-type, depending on P and M scores.(4) We assessed the extent to which the morale variables differed among the four leadership types. The results showed the pupil's school morale came highest under PM-type, followed by M-type or P-type, and the lowest under pm-type. This order was consistent with those found in the studies of other private organizations, government offices, and elementary schools.